I always like investigating assaults. You take the victims statement, to find that they are a completely upstanding member of the community, and the assault was utterly unprovoked, occurring without warning from a total drunken stranger. Oh, and they definitely weren't drunk, just 'merry'.
If you catch up with the stranger, you then find out from them that actually, they were simply minding their own business, doing nothing when for no reason, a drunk stranger came up and tried to punch them, so in self defence they hit them, whilst shouting 'I say!' before managing to run away. Oh, and hey definitely weren't drunk, just 'merry'.
Then you watch the CCTV and see two very drunk idiots, posturing up to each other for a good few minutes before performing a decent impression of either a) two windmills built too near each other in a hurricane or b) an Olympic swimmer practising front crawl the only way possible whilst standing, with no access to water. One of said drunken idiots then comes out ahead on points, and gets to stagger off proudly, whilst the other picks up the pieces of his wounded pride, and in an attempt to justify the whole situation, decides to report the matter to the police.
Ok, I shouldn't be so cynical, but in ten years of watching CCTV I've been surprised just ONCE, and actually congratulated the victim in that matter for possibly being the only 100% accurate and truthful statement I've ever taken!